For many years it has been known to utilize power driven devices such as mowers and cultivators, which make it possible for an operator to perform a substantial amount of work in a field as well as in and around and under trees with a minimum of effort and expense.
In areas where trees such as citrus trees are grown commercially, the limbs of the trees in many instances are heavily weighted by fruit, causing them to hang low, and frequently to present a substantial problem to a tractor operator concerned with mowing or cultivating, in that he must avoid injury to himself, to the trees, and to the fruit.
Before the advent of rotary implements that were laterally shiftable, it was not possible to effectively mow the growth or cultivate the soil beneath the low hanging branches of citrus and other trees in order to reduce the acidity as well as pests, generally promote the welfare of the tree, the yield of fruit, and enhance appearance.
In accordance with our U.S. Pat. No. 2,777,272 entitled UNDER TREE MOWER AND HARVESTER, which issued Jan. 15, 1957, we taught a mower and harvester which could be projected and retracted at the behest of the operator. Normally the rotary implement is maintained in the outward position found most effective, but as the tractor neared a tree, the rotary implement can be retracted laterally, so as to avoid tree contact. In that patent we taught an implement suspension arrangement involving multiple hinge points, thus enabling the implement to have a floating type characteristic such that is easily followed ground contours. In that patent we also taught the use of a number of discrete, chain driven rotary cutters disposed at spaced locations along the longitudinal axis of the cultivator, with it being possible for the operator to pivot the entire cultivator assembly upwardly on occasion.
Our U.S. Pat. No. 2,882,978 entitled "UNDER TREE CULTIVATOR" was concerned with a similar teaching, but involved a novel extensible frame arrangement, as well as featuring all hydraulic controls.
Our U.S. Pat. No. 2,976,663, which issued Mar. 28, 1961, entitled "UNDER TREE HOE MOWER" was also similar in making it possible to mow or cultivate in and around trees, but this devide utilized a mounting arrangement including a bracket attached adjacent a portion of the engine by means of bolts, and while this arrangement was highly effective, it involved a rather complicated procedure to install the cultivator or mower on the tractor, and a considerable amount of effort to later remove it from the tractor. As a result, a tractor equipped with an under tree cultivator mower typically was set aside and not used for other duties. This of course increased the financial demands on the grower, for it was therefore necessary for him to either undertake the time and effort involved in the removal of the cultivator equipment when the tractor was to be used for other purposes, or else involved him having to undertake the expense of purchasing an additional tractor to be available for non-under tree use.
All of the under tree devices previously patented were not limited to cultivators utilizing a plurality of rotary cutters disposed at spaced locations along the centerline of the cultivator, for in accordance with our U.S. Pat. No. 3,181,619 which issued May 4, 1965, that cultivator utilized an elongate shaft running the length of the cultivator, with such shaft having a number of ground-engaging teeth thereon, and with the centerline of the shaft disposed perpendicular to the longitudinal centerline of the tractor.
Other patentees have obtained patents on similar equipment in which power for the cultivator or mower was obtained from the power take-off unit of the tractor. Such prior art patents include the Alzani et al U.S. Pat. No. 3,183,978 and the Wathen U.S. Pat. No. 3,313,094. Each of these involved a shaft arrangement extending generally forwardly from the power take-off unit at the rear of the tractor, but unfortunately, such designs involved such forwardly extending shaft running inboard of the large drive wheel at the right rear of the tractor. The close-by location of the large wheel necessarily placed a restriction on lateral shaft movement, and therefore on lateral cultivator movement. This coupled with the usual difficulty of providing cultivator support structure that could be added to or removed from the tractor rapidly meant that such agriculteral devices and equipment enjoyed scant commercial success. It was a desire to improve upon these burdensome arrangements of the prior art that occasioned the novel and highly advantageous design in accordance with the present invention.